May 5, 2010 -- Older men living with wives who have dementia have an almost
12-fold increased risk for developing dementia themselves, a new study
shows.

Elderly women in the study whose husbands developed dementia had a fourfold
increase in dementia risk.

A strong body of research has linked caring for a spouse with Alzheimer's
disease to depression, poorer overall health, and even earlier death.

The new study shows greater intellectual declines among the spouses of men
and women with Alzheimer's or other age-related dementias, study researcher
Maria Norton, PhD, of Utah State University tells WebMD.

"The association was strong for both men and women, but the good news is
that most people in the study did not develop dementia even when their spouse
did," she says.

Dementia Risk Among Married Couples

The investigation included 1,221 married couples residing in Cashe County,
Utah, who were participants in a large, ongoing study of memory, health, and
aging.

All the participants were 65 years old or older at enrollment and none
showed evidence of dementia.

Up to 12 years later, however, dementia had been diagnosed in the husband
alone in 125 couples and in the wife alone in 70 couples. In 30 couples, both
the husband and wife had developed dementia.

After taking into account well-known risk factors for Alzheimer's disease,
including age, sex, genetic predisposition, and socioeconomic status, having a
spouse with dementia was associated with a sixfold increase in dementia risk
(11.9-fold increase in risk among men and 3.7-fold increase among women).

The study participants were not asked if they were the caregivers for a
spouse with dementia, but most lived in the same home with these spouses after
they were diagnosed.

The findings are published in the Journal of the American Geriatrics
Society. The National Institute on Aging funded the research.

Manage Stress, Reduce Risk

Norton says more research is needed to determine if certain elderly
caregivers are more vulnerable than others and to identify interventions that
may reduce the risk.

University of Washington professor of psychiatry Peter P. Vitaliano, PhD,
agrees. Vitaliano has studied the physical and psychological impact of caring
for chronically ill loved ones for many years.

He says study after study shows that spouse caregivers are more likely than
noncaregivers to be depressed, socially isolated, and neglect their own
health.

His own research suggests that the stress hormone cortisol plays a major
role in dementia by increasing insulin levels. There is evidence that excess
circulating insulin in the brain causes lesions similar to those believed to
cause Alzheimer's disease.

"It is clear that depression and stress hormones affect memory and the
brain," Vitaliano tells WebMD. "Caregivers often report chronic stress, which
means they are pumping out a lot of cortisol."

His research also suggests that caregivers who manage stress with
antidepressants, exercise, and a strong social network have better overall
health.

"It amazes me that caregivers often think that denying their own needs makes
them better caregivers," Vitaliano says. "In reality, the complete opposite is
true."